In a magazine interview about watercress and other wild foods, Mr Worrall Thompson said the weed henbane was "great in salads".
Healthy & Organic Living magazine's website has now issued an urgent warning that "henbane is a very toxic plant and should never be eaten".
The chef had meant to recommend fat hen, which is a wild herb.
Mr Worrall Thompson, currently on holiday in Spain, told the BBC the mix-up was "embarrassing - but one of those genuine mistakes".
Henbane - Hyoscyamus niger - has sticky serrated leaves, yellow, funnel-shaped flowers and a stale scent.
Its name has Anglo-Saxon origins - meaning killer of hens - and it can cause hallucinations, drowsiness and disorientation in humans.
Larger quantities can cause a loss of consciousness, seizures, trembling of the limbs and, in extreme cases, death.
From Worrall Thompson's side this can probably be viewed as an honest mistake, the sort of slip of the tongue that surfaces in casual speech. On the other hand the same cannot be said where the responsibility for editing Healthy & Organic Living is concerned:
Healthy & Organic Living magazine's editor Kate Collyns has written to subscribers to apologise.
Her publication's website gives this advice: "As always, check with an expert when foraging or collecting wild plants."
So Collyns has taken appropriate damage control steps on her Web site and for her subscribers. Did it occur to her to send out inserts to magazine stands, or would this be too much to ask of the shopkeepers? More importantly, however, is the question of how seriously Collyns takes her job of actually editing. Does she believe that, where an interview is concerned, whatever the subject says is immune from fact-checking? Is her knowledge of English so impoverished that the suffix "bane" did not raise a red flag when she saw it (giving her the benefit of the doubt that she actually did see it)?
I continue to hammer away at my primary point: You cannot have quality content without quality editing. Editing is a professional skill that needs to be treated as such in both work practices and compensation. It requires levels of both judgment and synthesis that can never been handed off to "the crowd." It is a personal responsibility, which is why responsible parties are named on a periodical's masthead. Ironically, in light of Nicholas Carr's recent "Is Google Making Us Stupid?" essay, Collyns might have done a better job if she had thought to use her Google search tool. I just typed in "henbane;" and my first hit was the Wikipedia entry. Whatever we may think about the reliability of Wikipedia, the content of this page should have at least raised a red flag!